Drug delivery devices, which allow multiple dosing of the required dosage of liquid drug and administration of the liquid to a patient, are well known in the art. Generally, such devices have substantially the same purpose as that of an ordinary syringe.
Injectors of this kind must meet a number of requirements to match a user's needs. The devices have to be robust in construction, yet easy to use both in terms of the manipulation of the parts and understanding by a user of its operation. In the case of those with diabetes, many users will be physically infirm and may also have impaired vision. Where the injector is to be disposable rather than reusable, the injector should be cheap to manufacture and easy to dispose of. Preferably, the drug delivery device should be suitable for recycling.
Typical drug delivery devices, e.g. pen-type injectors comprise numerous components, such as a housing, a cartridge holder and a drive mechanism, wherein the drive mechanism is adapted to apply thrust on a piston of a cartridge containing the medicinal product or drug to be dispensed in doses by the device. At least some of the components of such drug delivery devices, in particular a removable cap, a housing and/or a cartridge holder are manufactured as injection moulded plastic parts that are generally demanded to fulfil requirements regarding mechanical stability and rigidity and yet generally have to comply with low cost demands regarding the manufacture of such devices.
Usage of user- or patient-operated injection pens and drug delivery devices is growing in number due to a manifold of diseases requiring injection of a respective medicinal product or liquid drug. Among these, diabetes requiring hypodermic or subcutaneous administering of a liquid drug like insulin, plays a predominant role.
Disposable or single-use drug delivery devices typically turn to plastic disposal after use and therefore constitute a burden on the environment, in particular if disposed in landfills.